1. Field of the Invention
The present invention relates to a heating system, a heating method and a program, each adapted for heating an object to be processed, such as a semiconductor wafer or wafers.
2. Background Art
In a process for manufacturing semiconductor devices, the heating system adapted for performing a film forming process for the object to be processed, such as the semiconductor wafer or wafers, is employed. In the heating system, various processing conditions, for example, a processing temperature, a processing pressure, a gas flow rate and the like, are determined, depending on, for example, a kind, film thickness and the like of a thin film to be formed, and a recipe, in which these processing conditions are described or fixed, is prepared for this system. For instance, by selecting such a recipe corresponding to the kind and film thickness of the thin film, a film-forming process and the like can be performed based on such predetermined processing conditions.
However, in the heating system, although it can provide an appropriate process at the start of operation, extraneous matter will be gradually attached and accumulated onto a wall of its furnace through a plurality of repetitions of the operation. With increase of film thickness of such accumulated extraneous matter, the temperature in the furnace will be lowered even though the operation is controlled under the same processing temperature. In such a manner, when the processing temperature for heating the semiconductor wafers is lowered and gets out of the processing conditions, uniformity between batches will be degraded, and/or it will be quite difficult to form a thin film of a desired film thickness onto each semiconductor wafer.
In a technique, for example, TOKUKAI No. 2003-109906, KOHO, which was proposed to address such a problem, a semiconductor manufacturing apparatus is described, which can enhance the uniformity between the batches by performing temperature control in accordance with a relationship between the accumulated film thickness and temperature required for forming the thin film.
Patent Document 1: TOKUKAI No. 2003-109906, KOHO
In TOKUKAI No. 2003-109906, KOHO, five zones are provided in the heating furnace in order to establish the relationship between the accumulated film thickness and the temperature to be corrected, such that, for example, when the accumulated film thickness becomes Aμm, the temperature is increased by B° C., thereby performing the temperature control for each zone in the furnace in accordance with this relationship. However, even with such temperature control, it is difficult to mechanically or automatically control the temperature in the furnace to a designated processing temperature, and thus an operator must perform the temperature control by experience and/or intuition. Therefore, a need still remains for the heating system and/or heating method, by which even an operator having no information and/or experience concerning the heating system and/or process can readily control the heating temperature.
The present invention was made in light of the above circumstances, and therefore it is an object of this invention to provide the heating system, the heating method and the program, which can control the processing temperature with ease, and which can provide an appropriate heating process to the objects to be processed.